scholarly journals Plasma hormone concentrations associated with early embryo mortality in heifers

2019 ◽  
Author(s):  
Hansel W.
Keyword(s):  
Early Embryo ◽  
Embryo Mortality ◽  
Plasma Hormone

Fertility in Cheviot ewes. 2. The effect of level of pre-mating nutrition on ovulation rate and early embryo mortality in North and South Country Cheviot ewes in moderately-good condition at mating

1979 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney ◽  
W. F. Smith
Keyword(s):  
Food Intake ◽  
Good Condition ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Restricted Feeding ◽  
Embryo Mortality ◽  
The North ◽  
Breed Difference ◽  
High Level

ABSTRACTIn two experiments over 2 years, 57 North Country Cheviot and 82 South Country Cheviot hill ewes were differentially group-fed indoors over a 2-month period to achieve either good or moderate body con- dition. Over 5 weeks prior to mating, ewes in good condition were brought down in condition by restricted feeding and ewes in mod- erate condition were raised in condition by a high level of feeding. The ewes were thus in moderately-good condition at mating. After mating, ewes were maintained in this condition until killed either on return to service or at 29 ± 8 days for counts of corpora lutea and viable embryos.Ovulation rate in each breed was positively related to the level of pre-mating food intake at the condition level studied. Embryo mortality, as ova loss, was not influenced overall by the level of pre-mating food intake but loss of multiple-shed ova was greater than that of single-shed ova in ewes which had been on restricted feeding before mating. Although a greater proportion of ewes in the North Country Cheviot breed were not pregnant at slaughter, this could not be identified as a breed difference since the breeds were studied in different years.

Comparing early embryo mortality in dairy cows during hot and cool seasons of the year

1990 ◽  
Vol 33 (1) ◽  
pp. 314 ◽  
Author(s):  
D.P. Ryan ◽  
J.F. Prichard ◽  
E. Kopel ◽  
R.A. Godke
Keyword(s):  
Dairy Cows ◽  
Early Embryo ◽  
Embryo Mortality

Embryo mortality in maiden hereford x friesian heifers following embryo transfer

1992 ◽  
Vol 1992 ◽  
pp. 46-46
Author(s):  
D. Pullar ◽  
K F D Brown ◽  
A E Wrathall
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Pregnancy Loss ◽  
Early Embryo ◽  
Cattle Breeding ◽  
Embryo Mortality ◽  
Cytogenetic Abnormalities ◽  
Frozen Embryos ◽  
Fresh Embryos

Early embryo mortality results in significant inefficiency in cattle breeding. A pregnancy rate of 65-70% to a single service, AI or transfer of fresh embryos is considered to be very good indeed. A pregnancy rate of 55-60% using frozen embryos would also be considered very good. Of the 30%, or so, of cattle which do not become pregnant to a single service, approximately one quarter are accounted for by fertilisation failure (Diskin and Sreenan, 1980; Roche et al, 1981) and another quarter by cytogenetic abnormalities in the embryos, which usually occur within the first few days after fertilisation (Hare et al. 1980; Gayerie de Abreu et al, 1984). Failure in the communication between embryo and uterus probably accounts for the remaining 50% of pregnancy loss. Fertilisation failure and early deaths due to cytogenetic abnormalities are by-passed by embryo transfer (ET) so that other causes of loss become rather more significant.

The interaction of nutrition and body condition at mating on ovulation rate and early embryo mortality in Scottish Blackface ewes

1975 ◽  
Vol 85 (3) ◽  
pp. 465-470 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney
Keyword(s):  
Food Intake ◽  
Body Condition ◽  
Good Condition ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Service Rate ◽  
Corpora Lutea ◽  
Embryo Mortality ◽  
Poor Condition ◽  
High Level

SUMMARYOne hundred and fifty-six Scottish Blackface ewes were differentially group-fed over a 2-month period to achieve three distinct levels of body condition (good, moderate and very poor). Over 5 weeks prior to mating, one group of good-condition ewes was maintained in that condition, one group of good- and one of moderate-condition ewes were brought down in condition by restricted feeding and one group of moderate and the very poor condition ewes were raised in condition by a high level of feeding. Ewes were therefore in good, moderately good or poor condition at mating. After mating, ewes were killed either on return to service or at 25 ± 5 days for counts of corpora lutea and viable embryos.Poor body condition, irrespective of feeding level, was associated with a delay or suppression of oestrus and with a high return-to-service rate. Ovulation rate was positively related to body condition at mating but not to the level of pre-mating food intake at the condition levels studied.Embryo mortality decreased as body condition at mating increased and the interaction between condition and the level of pre-mating food intake had a differential effect on mortality of single- and multiple-shed ova. The lowest rate of embryo mortality was found in ewes in moderately good condition which had been well-fed before mating.

Fertility in Cheviot ewes. 1. The effect of body condition at mating on ovulation rate and early embryo mortality in North and South Country Cheviot ewes

1979 ◽  
Vol 29 (1) ◽  
pp. 11-16 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney
Keyword(s):  
Body Condition ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Embryo Mortality ◽  
Breed Type ◽  
The North ◽  
Breed Difference ◽  
North And South ◽  
Lambing Rate

ABSTRACTIn two experiments over 2 years, 113 North Country Cheviot and 132 South Country Cheviot hill ewes were differentially group-fed over a 10-week period to achieve either good or moderate body con- dition. Ewes were maintained in these levels of condition over the 5 weeks prior to mating. After mating, ewes were killed either on return to service or between days 23 and 85 for counts of corpora lutea and viable embryos.Ovulation rate in each breed was positively related to body condition at mating. Embryo mortality, as ova loss, was not influenced overall by breed, type of ovulation, year of recording, or body condition. Although comparisons of loss were partly confounded by a differen- tial distribution in the number of ova shed in each breed and body condition group, there was an apparent breed difference in loss of single- and multiple-shed ova. Potential lambing rate therefore showed greater response to improved body condition at mating in the North Country Cheviot breed than it did in the South Country Cheviot.

Unhatched eggs: methods for discriminating between infertility and early embryo mortality

Ibis ◽  
2008 ◽  
Vol 150 (3) ◽  
pp. 508-517 ◽  
Author(s):  
T. R. BIRKHEAD ◽  
J. HALL ◽  
E. SCHUT ◽  
N. HEMMINGS
Keyword(s):  
Early Embryo ◽  
Embryo Mortality

102 A delay in maternal zygotic transition may lead to early embryonic loss in poor-quality bovine blastocysts

2020 ◽  
Vol 32 (2) ◽  
pp. 177
Author(s):  
H. Georges ◽  
J. Bishop ◽  
H. Van Campen ◽  
J. Barfield ◽  
T. Hansen
Keyword(s):  
Assisted Reproductive Technologies ◽  
Reproductive Technologies ◽  
Poor Quality ◽  
Early Embryo ◽  
Fold Change ◽  
Differentially Expressed ◽  
Cell Permeability ◽  
Embryo Mortality ◽  
Maternal Mrna ◽  
Mrna Transcripts

Increased genetic potential and performance of dairy cows has coincided with a decline in fertility. Early embryonic mortality accounts for 75-80% of this decline in fertility, costing the industry over $1.28 trillion worldwide. Despite advancements in assisted reproductive technologies and embryo transfer, many transferred embryos do not survive past Day 24 of gestation, suggesting flaws in embryo selection for transfer. It was hypothesised that visually lower-quality IVF Day 7 blastocysts were developmentally delayed as a result of altered mitotic signalling and were at higher risk of embryo mortality. To identify potential causes for early embryo mortality in IVF embryos, RNA-Seq was performed on 6 categories of Day 7 blastocysts: stages (S) 5 (early), 6 (full), and 7 (expanded), with quality scores (Q) of 1 or 2. Oocytes were matured, fertilized by routine procedure, and cultured for 7 days. Blastocysts were classified and graded, separated into the six categories, and subjected to Pronase digestion of the zona pellucida. From three biological replicates of each blastocyst group, RNA was extracted and submitted for RNA-sequencing. Secondary bioinformatics and analyses were performed using R to determine differentially expressed genes. When S7.Q1 blastocysts were compared to other categories, 55 genes were consistently differentially expressed (P<0.05) in S5.Q1 or 2 and S6.Q2. Of these 55 genes, 15 were significantly upregulated (>1.5 fold change), and 40 were downregulated (<−1.5 fold change). The nine most common upregulated genes in S5.Q1 or 2 and S6.Q2, compared with S7.Q1, were BTG4, ARGFX, GPC4, BOC, CNTNAP2, NR3C2, CCDC7, and PHYHIPL. The five most common downregulated genes included MUC1, HSD3B1, ADAM19, EVPL, and TGM1. The EVPL and TGM1 proteins are associated with cell barrier permeability, and a lack of TGM1 has been shown to cause neonatal death in mice. Therefore, early embryo mortality may begin with decreased EVPL and TGM1, limiting cell permeability and communication between blastomeres. This limited communication might delay gene expression in the embryo at the 4- to 8-cell stage, delaying the maternal zygotic transition (MZT), in spite of continued cell division. This explanation is supported by the observed increase in ARGFX and BTG4 mRNA. Normally, stored maternal BTG4 mRNA becomes translated during the MZT and degrades maternal mRNA. The increase of BTG4 mRNA in poor-quality embryos may reflect delayed translation of BTG4 and delayed MZT. The mRNA transcripts increased in poor-quality blastocysts may be excess maternal mRNA not yet degraded, like BTG4. The decreased mRNA transcripts observed may be indicative of zygotic genes which have not yet been transcribed. For instance, MUC1 is necessary for proper embryo implantation, and HSD3B1 converts placental pregnenolone to progesterone and produces a precursor to oestradiol. The delayed transcription of both MUC1 and HSD3B1 may impair maternal recognition of pregnancy, implantation, and communication to the maternal endometrium via oestradiol, thereby causing embryo mortality. This research was supported by USDA NNF 2016-38420-25289 and Zoetis Inc.

scholarly journals 138EARLY EMBRYO MORTALITY IN BUFFALO (BUBALUS BUBALIS) DURING THE SPRING PERIOD

2004 ◽  
Vol 16 (2) ◽  
pp. 191
Author(s):  
G. Neglia ◽  
C. Grassi ◽  
A. Prandi ◽  
G. Galiero ◽  
E. De Carlo ◽  
...  
Keyword(s):  
Bubalus Bubalis ◽  
Early Embryo ◽  
Pcr Analysis ◽  
Blood Levels ◽  
Infectious Agents ◽  
National Meeting ◽  
Embryo Mortality ◽  
Pregnancy Diagnosis ◽  
Spring Period ◽  
Group B

Embryo development is linked to several factors, such as intrinsic defects within the embryo, an inadequate maternal environment or failure of maternal response to embryonic signals. Reproductive seasonality in buffalo species (Bubalus bubalis) is responsible for the lower reliability of the pregnancy diagnosis by progesterone assay in spring, probably due to the high incidence of early embryo mortality (EEM) for hormonal reasons (Campanile et al., 1989; Proc. 2th National Meeting ‘Studio dell’efficienza riproduttiva degli animali di interesse zootecnico’: 51–57). The aim of the study was to identify the causes of EEM in buffaloes inseminated during the spring period. Italian Mediterranean Buffalo cows (n=209) in a good state of health were synchronized using the Ovsynch-TAI Program (Pursley et al., 1995 Theriogenology 44, 915–923) and inseminated 16 and 40 hours after the second administration of GnRH. Artificial inseminations were performed by the same technician. Ten to 20 days after the first insemination two blood samples were collected from each animal for assessing P4 levels by RIA. Days 24 and 40 after the first insemination, pregnancy diagnosis was assessed by rectal ultrasonography (Aloka SSD-500) with a 5MHz sector scanner. In animals with EEM a uterine flushing was carried out and recovered fluid was analyzed for the principal infectious agents. Microbiological analyses were carried out according to Quinn et al. (1994 Clinical Veterinary Microbiology, Wolfe Publishing, Mosby, Europe) and a PCR analysis was performed only for Bubaline Herpes Virus (BuHV1), Toxoplasma and Neospora. Statistical analysis was assessed by Student’s t-test. The incidence of cyclic buffaloes after synchronization treatment (94%) and pregnancy rate at 40 days (34.4%) were similar to those reported in a previous study (Neglia et al., 2003 Theriogenology 60, 125–133). EEM between 24 and 40 days was 45% and only in 9 buffaloes (15.3%), these results correlated with the presence of infectious agents (Streptococcus spp. group B and G, Bacillus licheniformis, Proteus mirabilis, Staphylococcus spp.). P4 levels on Day 10 were higher (P<0.05) in pregnant (P) buffaloes than in those with EEM. On Day 20, P4 levels were higher (P<0.01) in P buffaloes than in those with EEM and those not pregnant. It is hypothesized that the reduced activity of hypophysis, correlated with an increase in hours of light, may be responsible for decreased P4 concentrations and EEM in buffalo. Table 1 P4 blood levels in pregnant (P) and non pregnant (NP) buffaloes and in buffaloes with EEM 10 and 20 days after insemination

The effects of live weight on the ovarian response to pregnant mare serum gonadotrophin and on embryo mortality in the ewe

1971 ◽  
Vol 76 (1) ◽  
pp. 177-178 ◽  
Author(s):  
J. C. Guerra ◽  
C. J. Thwaites ◽  
T. N. Edey
Keyword(s):  
Live Weight ◽  
Ovarian Response ◽  
Early Embryo ◽  
Embryo Mortality ◽  
Ambient Temperatures ◽  
Factors Associated ◽  
Specific Factors ◽  
Pregnant Mare Serum Gonadotrophin

Despite the fact that early embryo mortality commonly leads to the loss of 25% of fertilized ova in ewes (Edey, 1969), little is known of factors associated with this loss. Severe, acute undernutrition (Edey, 1966) and high ambient temperatures (Dutt, Ellington & Carlton, 1959) are specific factors which are known to cause embryo death, but these do not normally occur in most sheep producing areas.

Sign in / Sign up

Export Citation Format

Share Document